Transmission gearing



`June 19, 1928. 1,674,082

c. E. F. AHLM TRANSMISSION GEARING Filed Sept. 4, 1926 Patented June 19, 1928.

UNITED STATES CHARLES-E. E. AHLM, OE CLEVELAND, OHIO, AssIoNOIf To ING COMPANY, OE CLEVELAND, OHIO, A CORPORATION or DELAWARE.

PATENT OFFICE.

AUTOMOTIVE PATENT TRANSMISSION GEARING.

Application ma september 4, 192s. serial' Np. 13am.

This invention relates to transmission gearing. The object is to provide a very compact and quietly operating change speed transmission. further object is to provide a change speed gearing which will be ca-I pable ot' connecting a pair of shafts for direct drive and at different speeds which' will be strong and compact and very easily operated to change from one speed to another.

More specifically,- it is an object to provide an improved change speed gearing employing internal and external gears for connecting two rotatable members in different speed relations, which may bc'easily and cheaply manufactured and easily operated.

, In the embodiment shown in the drawing, my gearing isadapted to serve as a single over drive (or under drive depending on its relative position to the engine and axle of an automobile, for example) The employment of internal and external gears in mechanism of this character has been found to be very desirable partly because of their compactness when assembled, and partly 'be` cause they have been found to be much more quiet in operation than spur gears. With the use of such gearing it has been found very 'practicable in order to obtain a single change of speed and direct drive between the pair of shafts to be coupled, to use four sets of gears each of a different diameter than the others` and `clutch means for connecting the shafts directly. By my invention I have eliminated two of such sets 0f gears.

Another method Vpreviously known requires but two sets of gears. This consists in moving an external gear relative to an 'internal gear and an internal dental clutch,

in su'. h a manner that the external gear may engage the internal gear and clutchv selectively, the external gear in such case serving both as a-pinion and dental clutch member. This has a disadvantage namely that it necessitates laterally moving one or the other of the shafts which obviously requires considerable force. By my invention I use only one internal and' one external gear and I to this shaft.

am able to mount the shafts which are to be connected rigidly in `a casing,A and to eect the change from one speed to another through the intermediacy of a comparatively light clutch without disturbing the relation of the gears.

In the embodiment of my invention shown in the drawing one of the elements of the internal-external gear train is rigid with the driving shaft and the. other is rigidly mounted in the casin The driven shaft is-on the eccentric axis and connects with the driving shaft either through the gear train or through an axially inclined shaft havin a universal joint at each end.` A shifta le clutch is splined to the driven shaft .and operates to establish a dri-ving connection between the driving and driven shafts, either through the gear train or through the inclined shaft.

Further objects and features of the invention will become apparent from the follow- 1` ing description vpertaining to the accompanying, drawing, wherein I have shown my prefel-red `form. The essential novel 'character-` istics are summarized in the claims.

In the drawing, Fig. 1 is a central longitudinal cross section through a gearing 1ncorporating my invention; Fig. 2 is a detailed fragmentary cross section as indicated' along the line 2'-2 of Fig. 1; Fig. 3Vis a detailed fragmentary view showing the contour of the teeth in my preferred universal driving connection; Fig. 4 is av diagrammatic illustration showing the manner in which the teeth allow for the declination of one driving element to another.

Referring in .detail to uthe drawing and indicating 'the various parts by suitable characters, 1 designates a shaft which may, for example, be 'called the driving member and 2 another shaft, which in such case would be the driven member. These shafts, as shown' are connected for two speeds,.namely direct in a bearing eccentric nom drive and for a single diferent s eed. The

direct drive is Aestablished throug an inter- Ir.. '.liate inclined shaft 3 which is drvingly ally 4at 4 in the position shown in The other speed obtains when the clutch is in Y active vvhen a clutch device indicated gener- Fig. l.

and has a bearing support in the casing comprising rollers 20 and 21. As shown, the outer race 20 of the bearing 2O is supported by web portions l2b and 13b of the casing sections 12 and 13 respectively, the race thus serving as a pilot to align these casing sections. The rollers may bear directly upon the hub of the hollow gear member and are shown as retained in channels 22 formed in this hub. The bearings 21 are similarly supported in the web portion 13 of the casing section 13, there being channels 24 in the hub for the rollers similar to the channels 22.

The member 1 rotates on an axis eccentric to the axis of the hollow gear the amount of eccentricity being determined by the ratio of the gears 6 and 7, and is shown as supported at one end in a double ball bearing 25, and at the other by Ua single series of rollers 26, both sets of bearings being supported in the casin section 11.

The inclined sha 3, shown as arranged for connecting the members-1 and 2 for synchronous rotation, has at its ends, dental members 30 and 31, the former meshing with teeth 32 rigid with the member 1 and the latter meshin with internal teeth 33 in a member 18. ghe member 18 also serves as a clutch element, as will'be presently shown, and has a-projection 19 freely journalled in bearings 17 in an enlarged portion 16 of the member 2. The means for preventing endwise pla of the shaft 3, thereby maintaining the teet 30 and 33 in the desired relation, comprises spherical members, balls, 35 and 36 as shown, nesting in complementary reeesses in the ends of the shaft 1, member 18 and the inclined shaft. Such spherical members also afford additional lateral support for the inclined shaft. The action of the teeth in effecting an eicient universal driving connection will be hereinafterA set forth more in. detail.

The preferred clutching mechanismv for transmitting power selectivel throu h the members 3 and 5 comprises e ongate teeth 40 on the enlar ed portions 16 of the member 2, along w ich slide internal` teeth 41 on one end'of a slidable clutch rin 42. The clutch rin has at its other en internal teeth 43 w `ch, by reason of the sliding connection iO-41, may engage external teeth 44 on the member 18 or external' teeth 45 on the member 5. Thus the shaft 1 drives e member 2 through the universal shaft 3 whenv the teeth 43 and 44 are connected, and through the gear member 5 and teeth 6 and 7 when the `clutch teeth 43 and 45 are connected.

Itis 'undesirable to have either connection remain for any appreciable period of time in a neutral position, andin order that thev will not so remain, I have provided a quic shifting device whichl I will now describe. A

shifting fork is carried on a movable member 51 slidabl supported on an operating bar 52. The fbrk 50 engages the member 42 in a peripheral groove 53. When the bar 52 is moved toward the left as shown in Fig. 1, it compresses one of a pair of springs 58 located within the head by reason of a nut 57 threaded onto the bar, as shown, and normally positioned intermediately of the ends ofthe recess b the springs. When the bar is moved to t e left, for example. as shown in Fig. 1, the nut may be made to move the head 51 after slightly com rcssing thelcft hand spring 55, by reason o? engaging an abutment 58 on the head. After such engagement the head is moved along, carrying the ring 42 with it until the teeth 43 are between the teeth 1%44 and 45. At this time the Wedge point o a spring pressed plunger 60 ridesacross the polnt of a similarly wedge shaped projection 61 rigid with the head. The compressed spring 55 then insures the wedge points being thrown out of alignment, and thereafter the spring G3 lof the plunger eiects the shift independently of further manual movement of the operating bar.

The operating bar may be suitably con- `nected to a. lever or pedal at the operator`s position and may be made to extend 1n either direction from the gearin depending upon whether the gearin is to e used as an over drive or an under rive. l With the arrange ment shown it is simply necessary in order to ada t the gearing from an over drive to an un er drive, to reverse the position of the bar 52 by removing a bushing 65 and plug 66 from the recess 67replacing these parts in therecess 68, shown as surrounding the left hand end of the bar 52, and inserting the bar from the other direction.

The means whereby I am able to establish a connection between the laterally offset shafts which will be both compact and drivingly efficient, consists as shown in Fig- 4, in beveling o each working face of the teeth 30 and 31'as at 70 and 71,'the angle of such bevel being determinedl by the angle of declination between the axes of the connected members. By this means the horizontally disposed teeth namely those at right angles to .the teeth s own in full lines in Fig. 1, have their beveled surfaces substantially in full contact from a central rtion of each tooth to one end. The sur ace 70 for example, is shown in contact with the in- I adjacent tooth 33". This same conditionof course obtains withthe diametrically opposite teeth while all the other external teeth contact with the working surfaces of the internal teeth at their central or thickest portions, such' portions sliding from one'posi- .tion 'to another along the internalteeth as the members rotate. There may, of course, be a slight clearance between the meshing teeth, in order to eliminate anyv binding aci tion, but this does not have to be any greater 1 of which is constantly connected to one shaft, f

than the clearance between ordinary gear or clutch teeth.

In practice, these special teeth may be' very easily formed, for example, by setting up the shaft 3 in an arbor atan angle to the l path of the cutting tool, and milling out between adjacent teeth, cutting one surface 70 of one toothand one surface 71 of another at one strokeof the tool.

' From the above description it will be seen i that I have provided a gearing suitable ask a single reduction or single over-speed auxiliary transmissionor which may, if desired, be embodied in various ways in a2 complete change speed transmission. Vhen used as an auxiliary transmission, the gearing reuires but a small amount of space, is very light and durable and is aery quiet and efiicient in o eration. The universal connections for t e inclined shaft, may of course be varied from the form shown, or I may adopt other known devices for directly connecting two axially offset rotating members and the gearing may otherwise be considerably modified while keeping within the intended scope of my invention.

Havingl thus described my invention, I claimz` .1. In a gearing,two longitudinally separated shafts, a rotatable member having its V.axis inclined to the axes of the said shafts' and disposed intermediate of said shafts, an internal-externalgear train one element and means for selectively connecting the shafts through the intermediacy of the said rotatable member and through the gear train.

2. A change speed transmission gearing comprising two axially offset shafts, means including a shaft having a universal joint at both ends, one for each of said first mentioned shafts for connecting the shafts -directly together, a gear 4train for drivinglyl connecti these shafts for relative speed, 1 and clutc means interposed in each of the connections,

3. A gearing comprising^ two longitudi-I nally separated axially offset shafts, an 'axially inc ined rotatable member for connecting the same, clutch means interposed in gear, said internal Gear being drivingly con-' nected with one of5 said shafts, and clutch means for connecting ythe external gear to the other shaft.

5. Change speed transmission mechanism comprising two axially offset rotatable members, a gear train and clutch means associated therewith for connecting said members at a given s eed, and an inclined power transmitting s aft and clutch means associated therewithfor connecting the members at another speed.

6. In a gearing, two longitudinally separated axially offset shafts, direct 'drive coupling means therefor,- other coupling means comprising a gear train the elements whereof are axially parallel to 'the said'first mentioned shafts, one `element being permanently connected to one shaft and another element connectable to the other shaft, and means for rendering each of said coupling means drivingly idle when the other is active, whereby to change the drivingrelation of said shafts.

7. Change speed transmission mechanism comprising two shafts permanently out of alignment in fixed relation, an internal-external gear train* including a clutch arranged to drivingly connect said shafts in. 'such a manner that one rotates at a different speed from the other, and a member having a permanent driving connectionwithone of said shafts and an interruptable connection with the other, and extending through at least one of the gears for connecting the shafts for synchronous rotation.

8. Means for connecting two axially parallel shafts for different relative speeds, comprising an inclined rotatable member and a gear eccentrically mounted with reference to one of the shafts, the rotatable member and gear each having a permanentsaid shaft from a common source, one speed being transmitted through.` the hollow member and one through the other rotatable member.

10. In a gearing, a pair of rotatable members, one being hollow and the other extending thereinto with its axis displaced at an angle to the axis of the hollow member, a shaft and a clutch for connecting said shaft selectively with either of said rotatable members, another` shaft, and permanent driving connections between the latter shaft and both said rotatable members, one connection including a gear train whereby the driving ratio between said latter shaft and one rotatable membenis different than the ratio between this shaft and the other.

11. Means for connecting two axially offset shafts for different relative speeds', comprising an inclined shaft, and a hollow gear embracing the inclined shaft, in axial alignment with one of the said offset shafts, and geared to the other, and clutch means associated with both the gear and inclined shaft, so arranged that one of the offset shafts may drive the other through either the gear or inclined shaft.

12. In combination, two shafts tobe connected in different speed relations a clutch member associated with one shaft, an inclined shaft having a dental universal connection at either end thereof, one connecting directly with one of the shafts and the other with the clutch member, a hollow gear drivingly connected with the same shaft and surrounding the fsaid inclined shaft, clutch teeth on the hollow gear, and a movable clutch device arranged to cooperate selectively with the said clutch teeth and clutch member to drivingly couple the said first named shafts together either through the hollow gear or through the inclined shaft.

13. In a gearing, a pair of rotatable members to be connected, an intermediate member constantly connected to one of -said members and having an interruptable connection with the other for connecting said rotatable members for synchronous rotation, another intermediate member in surrounding relation to the first intermediate member and having a marient geared connection" with one of tg: rotatable members and an interruptable connection with the other for connecting the slid rotatable members in a different speed relation, one of said intermediate members having its axis intersecting the axis of one of the rotatable members for the purposevspecified 14. In a gearing, a pair of rotatable members, one being hollow and the other extendingthereinto at an angle, a shaft, means for connecting said sha selectively to said rotatable members in direct drive relation, and means including said connecting means for transmittin power at different speeds to said shaft' om a common source, one

speed being transmitted through the hollow member and one through the other rotatable member.

15. Change speed transmission mechanism comprising a rotatable member, a shaft, a hollow power transmitting member drivingly geared to the rotatable member, a clutch member associated therewith, a power transmitting member passing through the hollow member dentally connected to the said rotatable member, a clutch member associated therewith, one of said power transmitting members having its axis inclined to that of the other and a clutch membcr coacting selectively with both said clutch members and drivingly coupled with the shaft.

16.l Change speed transmission mechanism comprising two shafts permanently out of alignment in fixed relation, an internal-external gear train for drivingly 4connecting' said shafts in such al manner that one rotates at a differentspeed from the other, a shaft having its axis inclined to said first mentioned shafts and intersectin the axes of both for connecting the sha ts for another' speed relation, and clutch mechanism interposed between one of the shafts and said train and inclined shaft, arranged to select which of such connecting means shall be active.

17. Change speed transmission gearing comprising two axially offset shafts, a clutch element and a shaft having a universal joint at either end, one connected to one of the offset shafts and one to the clutch element for drivin ly connecting said offset shafts at one spec a gear tram for drivingly connecting said offset shafts at another speed, and a clutch movable to connect the offset shafts through the gear train and also to cooperate with said clutch element to connect these shafts through the universal joint shaft.

18. In a gearing, a rotatable member and a shaft in parallel and offset relation, teeth drivingly rigid with the rotatable member, teeth capable of being made rigid with the shaft, an intermediate connecting member having a universal dental connection at each end engaging respective sets of said teeth, and an internal-external gear train one element of which is drivingly rigid with the rotatable member, and means whereby the shaft may be connected to the rotatablel member either through the intermediate connecting member or. through the gear train.

19. In'a gearing, a `pair of shafts longirwithin the hollow member and permanently dentally connected to the same shaft, one

of said members having its axis inclined to the axes of the shafts, and clutch means whereby the other of said shafts may drive through either of the intermediate members.

20. In a gearing, a pair of rotatable power transmitting members, one being hollow and the other extendingv thereinto with its axis intersecting the axis of the hollow'member, a shaft, means for connecting said shaft selectively with said rotatable members, means for transmitting power through the rotatable members, one of the axially interrelation to said inclined member, a gear drivingly rigid with one of said shaftsand in mesh with said first named gear, means for coupling the other of said shafts selectively to the inclined member and to the first named gear, said inclined shaft having a universal dental connection with one of said shafts, the cooperating sets of teeth of the dental connection being so fitted as to eliminate play and beveled in both directions at an angle corresponding to the vangle of intersection of the axes.

22. In a transmission gearing, a pair of axially offset shafts, an inclined shaft intersecting the axes of both of said first mentioned shafts, a universal dental connection between one end of said inclined shaft and one of the said first mentioned shafts, and an interruptable connection between the other end of the inclined shaft and the other ofsaid offset shafts, a gear train drivingly connected with one of said shafts, clutch means for connecting the other of said first mentioned shafts with an element of said gearing, and means interposed between the inclined shaft and the said offset shaft to which it is universally connected for reventing end play of the inclined shaft W ile permitting it to rotate relative to` this shaft on an inclined axis.

23. In a gearing a pair of axially offset shafts to be connected in, different speed relations, an intermediate axially Ainclined member having a universal dental drivin connection with each of said shaftsone universal connection including a member intermediately of the inclined shaft and the respective offset shaft, a ear train drivingly connected intermediate y of said 'sh afts,

clutch means for rendering each intermedi-A ate connection drivingly acti=ve alternately, and balls at either end of the inclined shaft for preventing longitudinal play thereof. i

24. A change speed transmission gearing comprising two axially offset shafts, means including a shaft having a universal joint .at either end for drivingly connecting the said first mentioned shafts at one speed, a gear train for drivingly connecting these shafts at another speed, dentalclutch means interposed between each of the connections whereby one connection is active when theother is idle and resilient means for operating said clutch to effect rapid .transition from one connection to the other. n

25. A change speed transmission gearing comprising two axially offset shafts, means including an inclined shaft intersectin the axes of both of said first mentioned s afts for drivingly connecting these shafts at one speed, a gear train for drivingly connecting the shafts at another speed, clutch means including dental members rigid with an ele- -ment of the gear train and with the inclined shaft respectively, a cooperating Vmovable, clutch member drivingly connected with one of the first mentioned shafts, an operating member having a. connection with the movable clutch member comprising resilient means and a spring pressed plunger operat-` ing at right angles to the operating member for causing a rapid transition of the movable f clutch member from one clutching `position to another.

26. In a gearing, two axially offset rotatable members to be connected in different speed relations, intermediate means for connecting the members for synchronous rotation, means' including an internal-external gear train, one member of which is in surrounding relation t'o an element of the said intermediate means for connectin tatable members in a different spee relation, and means for rendering each connecting means drivingly active alternately.

27. Change speed transmission mechanism comprising two shafts permanently out of alignment, connecting means therefor comprising an internal gear and an external gear,

one being hollow and the other being connected to one of the shafts, other connecting means extending through the hollow gear for connecting the shafts in such manner that both rotate at the same speed, and means to render both connecting means inoperative.

28. In a gearing, two axially offset shafts to be connected in different speed relations, intermediate means for connecting the shafts for synchronous rotation, means for interrupting such connection, a hollow ear in eccentric relation to one of the sha ts and drivingly connected thereto, said intermediate means communicating through the holthe roi low gear, a driving connection between the rounding and geared relation to this memhollow gear and the other of said shafts and ber, the gear elements affording a difference l0 means to interrupt said latter connection. in speed between the members, and means 29. In combination a power transmitting for transmitting power from both members l5I rotatable member, a hollow power transto a common driven member.

mitting member having its axis in fixed in- In testimony whereof, I hereunto affix my clined relation to that of the first named signature.

member, said hollow member being in sur- CHARLES E. F. AHLM. 

